Test-retest Reliability of GPS derived Measurements in Patients with Claudication

Abstract

Despite the previously reported "within stroll" variability of walking bouts for distances, speeds, and stop durations, GPS derived greatest distance and average speed are reliable in PAD patients in test-retest experiments. The GPS appears to be a new tool to assess walking limitation and allows objective clinical investigation.

Real‐life adaptations in walking patterns in patients with established peripheral arterial disease assessed using a global positioning system in the community: a cohort study

“…Although treadmill walking assessments are considered as the ‘gold standard’ measurement of walking impairment in PAD patients with IC (Gernigon et al ., ,b), having the highest levels of reproducibility and reliability (Nicolaï et al ., ) they suffer from a number of disadvantages. They can be costly (as in most of circumstances, they are conducted under physician supervision in a hospital environment), have poor availability, are time‐consuming and repeat testing may be less frequent than desirable due to service restraints and equipment/personnel availability.…”

“…Global positioning systems has been proven to offer a reliable assessment of IC patients’ walking ability allowing testing to occur in conditions as close as possible to a usual walk (Gernigon et al ., ,b). Although some critique exists in regard to equipment cost and time needed to explain procedures to patients and to analyse findings (Lejay et al ., ), the benefits may supersede the disadvantages, even though additional testing of such devices may be necessary, in larger cohorts (Le Faucheur et al ., ; Gernigon et al ., ,b).…”

“…All participants completed all designated study visits. The sample size was estimated (with MWD being the main outcome measure), based on the number required on previous studies from authors in our group undertaken on the same population (Gernigon et al ., ,b). All participants had stable IC [4·4 (3·1) years’ duration], with a condition's duration ranging between 8 months and 11 years.…”

“…walking impairment questionnaire (WIQ)] (Ouedraogo et al ., ), Walking Estimated‐Limitation Calculated by History (WELCH) questionnaire (Myers et al ., ). The two questionnaires have been shown to have high correlation with the 6‐min walking test (Gernigon et al ., ,b) and treadmill walking assessments (Ouedraogo et al ., ). These tools, however, may not reflect accurately the true walking impairment or may be inappropriate for older or frailer patients.…”

“…These tests also fail to give an indication of the patients’ walking ability under ‘real’ conditions –such as walking that takes place in the community, and do not give information about walking speed or the number of stops between walking episodes. Global positioning systems (GPS) have been proposed as reliable, reproducible tools to measure total, mean and maximal walking distances in patients with PAD in community settings (Gernigon et al ., ,b).…”